Haloperfluoro and perfluoro mono- and polyethers which are ethylenically unsaturated can be homopolymerized or can be copolymerized with other ethylenically unsaturated monomers to form a melt processible, thermoplastic polymer.
An advantageous feature of such ethers which contain two sites of unsaturation, both a vinyl and an allyl group for example, is that they can be polymerized through one bond to form a melt processible, thermoplastic polymer, while the other bond remains unreacted in a side chain. This unreacted bond is then available to participate in a crosslinking reaction which converts the thermoplastic polymer to a thermoset.